Bidirectional optical assembly and method for manufacturing the same

Abstract

The present invention provides a bi-direction optical assembly with two optical transmitting channels by a small-sized package and relatively low cost. In the bi-directional optical assembly, the first transmitting optical subassembly (TOSA) and the receiving optical subassembly (ROSA) are optically coupled with the optical fiber via the inner housing. While the second transmitting optical subassembly is optically coupled with the optical fiber via the outer housing slidable to the inner housing.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a bidirectional optical assembly, in particular, the invention relates to a bidirectional optical assembly having two ports for an optical transmitter.[0003]2. Related Prior Art[0004]A bidirectional optical assembly comprises an optical transmitting subassembly (hereinafter referred by TOSA) for a transmitting channel, an optical receiving subassembly (hereinafter referred by ROSA) for a receiving channel, an optical fiber and a housing. The housing forms a tubular shape, one end of which secures the TOSA that is arranged along an axis of the tube, while, the other end thereof secures the optical fiber to optically couple with the TOSA in precise. On the other hand, the ROSA is supported in the side of the tubular housing and coupled with the optical fiber via an optical filter. Refer to Japanese patent application published as JP-2003-524789A.[0005]It is known that one type of the bidir...

AI Technical Summary

Benefits of technology

[0009]The first TOSA and the ROSA are preferable to provide wavelength selective filters to selectively transmit light with first and third wavelengths, respectively, which enables to reduce the optical noise.

[0010]Further, it is preferable to provide an isolator between the first and second WDM filters to transmit light propagating from the first WDM filter to the second WDM filter and to cut light propagating from the second WDM filter to the first WDM filter, which prevent light emitted from the optical fiber from returning the first and second TOSAs to become a noise source for the light-emitting devices installed within the first and second TOSAs.

[0012]Another aspect of the present invention relates to a method for manufacturing the bi-directional optical assembly. In the present method, first of all, the first TOSA permanently fixes in the position thereof by the YAG laser welding after aligning with the sleeve assembly via the inner housing. The first TOSA optically aligns with the inner housing along the direction parallel to the optical axis, while, the sleeve assembly optically aligns with the inner housing along directions perpendicular to the optical axis. Next, the second TOSA optically aligns with the outer housing along the direction parallel to the optical axis, while, the outer housing optically aligns with the inner housing along directions perpendicular to the optical axis. Thus, the first and second TOSAs may be aligned independently and separately along three directions against the optical axis, which attains a superior optical coupling efficiency.

[0014]Moreover, by securing the ROSA to the inner housing through the second alignment member, the ROSA may be aligned not only in two directions perpendicular to the optical axis but also in the direction parallel to the optical axis. Accordingly, the superior optical coupling efficiency may be attained for the ROSA.

Problems solved by technology

This type of the optical assembly is hard to miniaturize and is relatively cost un-effective because the assembly requires a number of optical element, for instance, the optical filter and the optical coupler.

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